Talk given October 1, 2007 for the UC-Berkeley Ear Club.

Richard F. Lyon
Google
Mountain View, CA

"Cochlea Modeling Retrospective"

There is a long history of cochlea modeling that people need to be
aware of, to help design, optimize, and evaluate neuromorphic hearing
systems. In particular, it's important to understand: the notions of
time-frequency and time-scale separation and the classes of filters
that these notions imply; the large-scale AGC and "essential"
nonlinearities that compress the wide dynamic range of sound into a
small representation range; the indirect relationship of transfer
functions to tuning curves; the relative properties of cascade and
parallel filterbanks; the need for higher-order poles to get
realistic transfer functions; why zeros are needed to keep the delay
realistic; and why and how to capture temporal structure for
subsequent processing. We review these topics and some early
contributions to this field.